Carbureter.



c. w. PROCHASKA.

CARBURETER.

APPLICATION FILED AUG-4,1915.

Patented; Sept. 25, 1917.

2 SHEETSSHEET 1.

IIVVE/VTOR WITNESS W c. w. IPROCHASKA.

CARBURETER.

APPLICATION FILED AUG. 4, I915.

1,%,@7 6o Patented Sept. 25, 191?.

2 SHEETS-HEET 2.

WI M1588 14 mar/Ms GROLL W. JEGKA, OF NEW YORK, EC, ASSIGNOR, BY MESNElW'NMENTS, T ACTUQ CURETOR & MANUFACTURING 60., INC., A CORPORNHON 015NEW YORK.

caaaman'ren.

Patented se t. 25, rat '3.

Application filed August 4:, 1915. fierml E530. ififlttl.

To all whom it mag concern: I

Be it known that l[, CARROLL W. PRO- CHASKA, a citizen of the UnitedStates, residing at 508 W. '122nd St., N. Y. (3., 1n 5 the State of NewYork, have invented certain new and useful Improvements inCarbureters,of which the following is a specification, reference beinghad to the accom panying drawings, forming a part hereof.

This invention relates to carbureters and has for itsgeneral objects toimprove the construction and operation of such devices and increasetheir eficiency under all con ditions of operationof the motor. Moreparticularly, the invention seeks to overcome many ob'ections which arefound in carburetors of own type and to meet the deficiencies of suchcarburetors by-including devices which not onl perform functions ro nowknown but, in addition, operate in such time relation to one another asto bring about a coordination demanded by the principles of physics forthe most eflicient operation of carburetors. In accordance with theinvention, account is taken of the relatively restricted area of thegasolene supply duct and the relatively large area of the port for theair supply whereby the volumetric proportions of gas and air underchanging pressures are very different from such volumetric proportionsunder normal runnin conditions, by reason of the restricte gasolenepassage. Compensation has been made for the disproportionate supply ofair'to the mixing chamber at the in;- stant of changes in pressuretherein, as is the condition in known carbureters by providin actuatingdevices for the needle valve and t e air valve which automatically causethe air valve to lag behind the gasolene valve upon initiation ofmovement of the latter. In this way the normal relative areas of thegasolene port and the air port are always altered upon initiation ofmovement of the gasolene valve so that the area of the gasolene port isincreased before the area of the air port is increased to acorresponding degree. In known structures, where the gasolene and airvalves move in harmony, the force opposed by the restricted gasoleneduct to an increased flow of gasolene is so great that an increase inthe volume of air is not accompanied immediately by a correspondingincrease in the volume of gaso- 55 lane and a lean mixture is taken intothe motor. The improved structure, as suggested above, overcomes thiscondition and insures a substantially fixed volumetric ratio between thegas and air at all times.

Figure 1 is a view in vertical section taken through the improvedcarbureter.

Fig. 2 is a view, partly in section and artly in plan, taken on theplane indicated y the hue 2-2 of Fig. 1 and looking in the direction ofthe arrows.-

Fl 3 is a view in section taken through the pat chamber on the planeindicated by the llne 33 of Fig. 1 and looking in the direction of thearrows, the other parts of the ,carbureter being omitted.

The casing a of the improved carbureter has formed therethrough at itscentral por- 1 tion a passage in which is disposed a Venturi tube 6 intowhich air is drawn for low speed from an air passage 0 and in theconstricted portion of which is introduced gasolene through a gasoleneduct 4 communicatmg with a gasolene reservoir 6 which is incommunication with the float chamber f. The low speed air'derivedthrough the air passage 0 commingles with the gasolene withdrawn throughthe duct d by the suctlon of the engine at the constricted part of theVenturi tube 1) and is drawn upward into a mixing chamber 9 into whichair for hlgh speed is drawn by the suctionof the motor, and the mixingis effected in this chamber prior to its passage past the butterflyvalve h to the motor, as is usual. The first feature of the invention isconcerned with the control of the port area of the gasolene duct (Z andthe port area of the main air supply for the mixing chamber 9, the airbeing drawn into the mixing chamber past the air valve indicated at Zand to which s ecific reference will be made hereinafter.

he gasolene duct d is controlled by a high speed traveling needle valve11 which may be adjustably mounted in a threaded sleeve is which is suported rotatably in the casing a of the car ureter and supports theneedle valve in proper relation to the mouth of the duct d. The sleeveis which rotates in the casing at and carries with it the needle valve2' and imparts axial movement to the latter, is connected through aswiveled pin is, link is and a second swiveled pin k secured to theother end of the link, to the supporting shaft h for the butterfly valveh. The connection described permits universal movement between theshaft'h' and the rotatable sleeve is so that actuation of the shaft byany usual devices results in simultaneous rota tive movement of thesleevelc and axial movement of the needle valve 5.: It will be evi dentto the skilled mechanic that other means for effecting the desiredrelative movement of the butterfly valve h and the needle valve 71 canbe employed, the invention not being limited to the precise means forbringing about such relative movement. Otherdevices, now to bedescribed, are interposedbetween the butterfly valve 71. and the airvalve Z so that movement of the butterfly valve with the needle valve2', in the manner described, will bring about, in the phase relationhereinafter pointed out, movement of the air valve. In the illustratedembodiment, the air valve Z is shown as carried on. a tubularshaft Zwhich, in turn, is mounted slidably on a fixed shaft m supported in thecasing a of the carbureter. Guided on the tubular shaft Z and preferablydisposed within the mixing chamber'g, so as to be protected thereby, isa grooved collar 01 which is held. yieldingly against axial movement byspiral springs 0 and p interposed, respectively, between the collar andthe air valve Z and a flange Z formed on the lower end of the shaft Z.This collar is engaged operatively by-a bell crank lever g supportedpivotally on a suitable bearing post a secured to the carbureter casinga and the free end of the bell crank lever g is connected to thebutterfly valve 71. through a link q secured pivotally to the face ofthe butterfly valve and to the bell .crank lever. From the descriptiongiven, it will appear that movement of the butterfly valve it causesmovement of the air valve Z through the link g' and one or the other ofthe springs 0, 32, according to the direction of movement of the valve.In the improved construction, the yielding connection just described isprovided in order that the movements of the valve Z will lag slightlybehind the movements of the butterfly valve 71. and the needle valve 2'.This phase relation in the movements of the elements referred to isinsured by a dash pot action effected by securing to all of the elements]l1St described for pur-- poses of adjustment, replacement or repair,the air port in the mixing chamber 9 is really formed as a ring a whichis screw threaded into the casing a of the carbureter and receives witha sliding air-tight fit the air valve Z. With this ring may be formedarms a? which permit the free passage of air through the ring when thevalve wall.

aaiaeve been described in some detail, it will be well to-ploint out thetheory of operationon which t 0 structure is based in order that theadvantages derived in a device of this character may be appreciated. IThe force opposed to any change in the rate of flow o gasolene throu hthe restricted duct d is very great, wh' e the supply of air for thegasolene is always permitted to flow into the mixing chamber 9 through arelatively large opening. Accordingly, if the area of the duct d issuddenly increased and the relative area of the air ort simultaneouslyincreased, the volume oi air inthe mixing chamber will immediately beproportional to the extent of the valve opening, whereas the volume ofgasolene drawn into the mixingchamber would, at the instant of increaseof the port area, be far less than that normally derived from the givenarea, due to the restricted mouth. This condition, which is to be foundin known carbureters, results in the induction to the motor of a leanmixture upon every change in. position of the valves. In the presentconstruction movement of the needle valve c' is not accompanied bycorresponding movement of the air valve Z but this last named valve lagsbehind the needle valve so that the intended volume of gasolene for anygiven port opening is permitted to flow into the mixing chamher beforethe corresponding volume of air is admitted. This coordination isessential to the development'of the highest degree of efficiency in acarbureter since. through it, the relative proportion of air to gas fora combustible mixture of the proper character, is maintained under allconditions of oper ation.

No reference has been made in the precedin description of the air valveZ to the specifIc character thereof inasmuch as the fea tures u on whichstress has been laid are not to be limitedto the specific form of theair valve. However, it has been found in practice that excellentresults. may be obtained in the new carbureter by forming the valve 2 asa cylinder with a scalloped or saw-tooth As shown in Fig. '1, the wall Zof the valve body has V-shaped recesses formed in the edge so that asthe valve is moved downward in the ring a the restricted portions of therecesses first pass the lower edge of the ring and establishcommunication between the mixing chamber 9 and the surroundinatmosphere. As the valve continues this downward movement, the width ofthe recesses and the volume of the openings through which the air passesincreases,

inmate not in a fixed ratio but in a variable and in creasin ratio, ashas been found to be most desirab e in carbureter practice, it beingwell understood that the proportion of air to gas may well be increasedas the volume of fuel fed to the motor is increased. This result issecured by the form of valve illustrated.

The float chamber is provided with a removable cover a in which isformed a supa vertically disposed tubular guide 6' for the float u. Thelever arm r extends into the tubular guide t through a slot t 'formed inthe wall thereof, so that the set screw 7" may rest loosely on thearcuate plate a and thereby determine the position of the lever arm 7*and the needle valve w. The plate 8 is held against accidentaldisplacement in the tubular guide 25 b means of suitable studs 8extendin latera y fromits faces and disposed wit out the tubular guide,the free end of the plate 8 being arranged so as to rest directly on theupper face of the float. In this way, movement of the float it .underchanging levels of the liquid within the chamber a is communi-' cateddirectly to the plate 8 and from it to the needle valve to through thelever arm 0-. However, it will be appreciated that it is desirable underdififerent conditions to make an initial adjustment between the-float uand the needle valve to so that the desired liquid level may be secured.This initial adjustment may be eflected readily in the illustratedembodiment by forming an opening a in the cover a directly above thehead of the adjusting screw r so that, upon removal of the screw cap afrom the opening (4 a suitable-tool, such as a screw driver, may beinserted through the opening and engaged with the screw and axialmovement of the latter eflected so as to change the fixed relationbetween the float u and the needle valve to in a manner which will beevident. B y movingthe screw r upward in an axial direction, the liquidlevel is raised in the float chamber, while contrary movement of thescrew r serves to bring about an adjustment which will insure a lower liuid level in the chamber. The adjustment Just described is especiallydesirable where the liquid within the float chamber a is kept under anappreciable pressure, as is usually the present da practice and isespecially useful in combination with the lever arm r whereby the forcetransmitted from the rising float u to the needle valve to is multipliedappreciably and a more certain regulation of the fuel supply therebysecured.

It will be noted that the tubular guide t which extends centrallythrough the annular float u is maintained in position by bosses a end aformed respectively in line with the guide on the bottom of the floatchamber a and on the inner face of the cover a so as to enter the guidewhen the parts are assembled.

A further feature of the improved float chamber and associated devicesresides in the simple construction of the plate 8 by which the movementof the float u is communicated directly-to the controlling devices forthe needle valve w. This plate 8, as mounted in the tubular guide t, haslimited free play in the guide so that it adapts itself automatically tochanging positions of the carbureter and yet serves under all condi-.tions to transmit the movements of the float.

From the float chamber a the gasolene flows through a passage (1 to thereservoir 6 from which it is withdrawn through the high speed supplyduct d in the manner pointed out. In a carbureter of this type, it isdesirable to provide an auxiliary gasolene supply passage through whicha limited amount of gasolene passes directly into the mixing chamber, bythe suction of the motor. Such a passage has been shown at e in Fig. land comprises conveniently a single tubular member which is threadedinto thelower wall of the casing of the carbureter and extends throughthe reservoir 6 oo into the mixing chamber 9 and places the reservoir incommunication with the chamber by openings 12 formed inits lower end toreceive gasolene and by a restricted opening c formed in its upper endand disposed was within the mixing chamber at a level above the normallevel of gasolene. This passage insures that a limited quantity ofgasolene will be drawn from the mouth 1: of the tube by suction of themotor, thereby supplying 110 a supplemental quantity of gasolene whichis not only useful as a starting charge but also during normal operationof the motor.

The operation and function of the several elements having been pointedout in connecits tion with the detailed description of each and theircoordinate operation having been particularly'referred to Where novelresults are. secured by such coordination, it is unnecessary to enterinto a separate descripmo tion ofthe operation of the carbureter as awhole. It is to be noted, however, that changes in the details ofconstruction of many of the parts and rearrangements thereof may be madeby those skilled in the art 125 without departing from the spirit of theinvention, the scope whereot is to be determined by the appended claims.

I claim as my invention:

1. In a carhureter, the comhination with 13o 4 Leeann the gasolene ductand the air part, of valves controlling the duct and the portrespectively, a single means actuating said valves, a yieldingconnection between the said actuating means and the air valve, and apositive connection between said actuating means and the gasolene valve,whereby movement of the gasolene valve is' followed by movement of theair valve.

2. In a carbureter, the combination with the gasolene duct and the airport, of valves controlling the duct and the port-respectively, abutterfly valve to control the flow of fuel to the motor, a positiveconnection between the butterfly valve and the gesolene valve, and ayielding connection between the butterfly valve and the air valve,whereby movement of the butterfly valve causes corresponding movement ofthe gasolene valve gasolene, an air valve, a mixing chamber, a

butterfly valve to control the flow of fuel from the mixing chamber, apositive connection between the butterfly valve and the gas'olene valve,and a yielding connection between the butterfly valve and the air valveextending through the mixing chamber and including a stem for the airvalve, a collar mounted on the stem, opposed springs seated on thecollar and expanding operatively against the'valve, and a linkconnection between the butterfly valve and the collar.

This specification signed this 2nd day of July,-A. D. 1915.

CARROLL W. PROCHASKA.

